Generally, containment sumps, underground storage tanks, sanitary sewers and other underground systems are buried below the frost line of the terrain surrounding the underground system. Access to these underground systems is oftentimes achieved through an opening or access point at ground level. These openings or access points may be large enough to provide physical access or entry into the system and a cover may be utilized to enclose or block access to the opening. Further, a cover support frame on which the cover rests defines the diameter or width of the opening or access point.
Below the grade or ground level a secondary access point may be constructed and a lid or secondary cover may be utilized to further confine access into the underground system. At times, it is desirable to reduce or eliminate water or other debris from flowing or infiltrating into the underground system. Although a cover may restrict the flow of water or debris into the underground system, water and other liquids tend to find the paths of least resistance and may find their way into the underground system. Further, many freeze/thaw cycles, erosion, or other influences may shift a cover on the support frame or otherwise create a path for liquids to leak into the system. Also, the expansions and contractions of the system may further compromise the system.
Prior devices have been described that attempt to create a secondary access point into the underground system, however these devices may allow liquids to penetrate into the underground system. No known prior device describes a cover for a secondary access point that includes an inflatable seal and that further contains the inflation mechanism within the lid itself.